Schools Chancellor Dennis Walcott spoke with students Ceesay Jangara, left, and Denim-Soloman Trotman, right, both 4, at the Harlem Village Academy in Manhattan.

The statistics released Monday looked awful: Nearly twice as many New York City public elementary and middle schools scored poorly enough on annual progress reports last year to be considered for closure.

In 2011-12, 217 schools received grades so bad – a D, an F, or a third consecutive C grade – they were automatically flagged for review, up from just 116 in the 2010-11 school year. The prospect that a school might close is scary for all involved – including parents, teachers, students and principals.

But scratch beneath the surface, and it becomes clear that groundwork for the statistical surge was set four years ago when unusually easy state tests were administered.

The jump last year was entirely attributable to schools that received a C grade or worse for three years in a row. For the last school year, 114 schools received a C after two years of similarly poor grades, while 103 received D’s and F’s. Two years ago, only five schools were flagged because they received a C or worse for three straight years.

That seems like a major jump – from only five schools to 114 schools that received their third straight bad grade.

But it was statistically impossible for more than 27 schools to fall into that category last year, thanks to a quirk in state tests four years ago.

In 2008-09, state tests were considered so easy that 97% of elementary and middle schools got an A or B on their annual progress reports, while less than 3% – only 27 schools – received a C, D or F that year.

In subsequent years, to try to compensate for changes in state tests, the city began grading its schools on a curve. Now, the top 25% of schools are A schools, 35% will get a B, 31% get a C, 7% a D and 2% an F.

That virtually ensured that the number of schools caught in the city’s first sweep of schools flagged for closure would increase dramatically this year.

“What’s really happened is the data has stabilized as a result of the unusual year,” said Shael Polakow-Suransky, the city’s chief academic officer and all-around wonk. “There was a glitch in the state testing system that created a bulge in As and Bs that year that’s now working its way through the system.”

Still, that means that more schools are given a once-over to determine whether there is something so structurally and managerially wrong with them that the city believes they can’t be saved.

The prospect that a school might close is worrying to parents concerned about the quality of education their child is receiving, and to teachers and principals, who could lose their permanent position at that building if the school closes. Generally, closing a school doesn’t mean immediately shutting its doors and kicking everyone out, but rather phasing out the school over the next few years while not admitting any more classes of freshmen.

In about a week, the city will narrow down the current field to a smaller group of schools that will be given greater scrutiny. Last year, the number of middle, elementary and high schools that made the second cut in the closure review was about 40 of the city’s district and charter schools, which numbered about 1,750 at the time. Eventually that was whittled down again by about half.

Will there be more schools targeted for closure this year?

City and Department of Education officials say it’s probable – but it’s not because on Monday there was a big increase in the number of schools that received three straight years of poor grades on progress reports. Instead, people close to City Hall say it’s likely because the Bloomberg administration wants to make as much of an impact as possible in its last full year in charge of the school system, and also because there were schools it wanted to close last year but couldn’t after a judge blocked the closures.